To affect drivers of vehicles to reduce speed at places like pedestrian crossings beyond the threat of fines it is known to use high-speed restricting devices. In its simplest form a high-speed restricting device consisting of a raised portion of the road, a so called road bump, can be used. A speeding vehicle crossing the bump is affected in a disturbing way. A disadvantage with this kind of device is that a vehicle crossing the bump at legal speed is affected in the same disturbing way. To avoid this, high-speed restricting devices have been developed, where the device raises a lid, a ramp or something similar, when a vehicle approaches the high-speed restricting device too fast. Vehicles driven by legal speed will not be affected by the high-speed restricting device. However, said restricting device is not only passed by cars but also by heavy trucks and industrial vehicles. The strain on the moving mechanics of the high-speed restricting device may be considerable, which means that known high-speed restricting devices with moving parts have proven to be short-lived and injury-prone. These known high-speed restricting devices are also exposed to effects from weather, sand and gravel.
GB 2333114 presents a high-speed restricting device comprising a contact plate held level with the road surface by a latch mechanism. At too high detected speed the latch is opened and the contact plate can be pressed down by a wheel of a traversing vehicle that receives a jolt when hitting an edge in front of the contact plate. When the vehicle has passed, a counter weight is expected to raise the plate again. If the plate would jam, a latch on the counter weight raises and is pressed down by the rear wheels or another vehicle. If a lorry with many axles would pass, the contact plate will be exposed to a considerable amount of activity.